| package org.apache.commons.jcs3.auxiliary.disk.indexed; |
| |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| |
| import java.io.Serializable; |
| |
| /** |
| * Disk objects are located by descriptor entries. These are saved on shutdown and loaded into |
| * memory on startup. |
| */ |
| public class IndexedDiskElementDescriptor |
| implements Serializable, Comparable<IndexedDiskElementDescriptor> |
| { |
| /** Don't change */ |
| private static final long serialVersionUID = -3029163572847659450L; |
| |
| /** Position of the cache data entry on disk. */ |
| long pos; |
| |
| /** Number of bytes the serialized form of the cache data takes. */ |
| int len; |
| |
| /** |
| * Constructs a usable disk element descriptor. |
| * <p> |
| * @param pos |
| * @param len |
| */ |
| public IndexedDiskElementDescriptor( final long pos, final int len ) |
| { |
| this.pos = pos; |
| this.len = len; |
| } |
| |
| /** |
| * @return debug string |
| */ |
| @Override |
| public String toString() |
| { |
| final StringBuilder buf = new StringBuilder(); |
| buf.append( "[DED: " ); |
| buf.append( " pos = " + pos ); |
| buf.append( " len = " + len ); |
| buf.append( "]" ); |
| return buf.toString(); |
| } |
| |
| /** |
| * @see java.lang.Object#hashCode() |
| */ |
| @Override |
| public int hashCode() |
| { |
| return Long.valueOf(this.pos).hashCode() ^ Integer.valueOf(len).hashCode(); |
| } |
| |
| /** |
| * @see java.lang.Object#equals(java.lang.Object) |
| */ |
| @Override |
| public boolean equals(final Object o) |
| { |
| if (o == null) |
| { |
| return false; |
| } |
| else if (o instanceof IndexedDiskElementDescriptor) |
| { |
| final IndexedDiskElementDescriptor ided = (IndexedDiskElementDescriptor)o; |
| return pos == ided.pos && len == ided.len; |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Compares based on length, then on pos descending. |
| * <p> |
| * @param o Object |
| * @return int |
| */ |
| @Override |
| public int compareTo( final IndexedDiskElementDescriptor o ) |
| { |
| if ( o == null ) |
| { |
| return 1; |
| } |
| |
| if ( o.len == len ) |
| { |
| if ( o.pos == pos ) |
| { |
| return 0; |
| } |
| else if ( o.pos < pos ) |
| { |
| return -1; |
| } |
| else |
| { |
| return 1; |
| } |
| } |
| else if ( o.len > len ) |
| { |
| return -1; |
| } |
| else |
| { |
| return 1; |
| } |
| } |
| } |